Reinforcing steel bar tying machine

ABSTRACT

A final gear ( 23 ) and a ball screw shaft ( 24 ) of a rotation drive system of a binding line twist mechanism are connected by a spline and a shaft portion of a center clamp plate ( 26 ) of a binding line clamp apparatus ( 25 ) is connected to a front end of the ball screw shaft ( 24 ). A shift mechanism for moving the ball screw shaft ( 24 ) and the binding line clamp apparatus ( 25 ) in a front and rear direction by a slide motor ( 22 ) is provided. A wire (W) is wound around a reinforcing bar (S) by a binding line feed mechanism, the wire is grasped by a front end portion of the binding line clamp apparatus ( 25 ) and thereafter, a shift mechanism applies a tension to a loop of the wire by moving rearward the binding line clamp apparatus ( 25 ). The binding line clamp apparatus ( 25 ) is rotated by a twist motor ( 21 ) and the shift mechanism twists up the wire by moving forward the binding line clamp apparatus ( 25 ). Since the wire is applied with the tension and twisted, a reinforcing bar binding strength of the wire loop is stabilized.

TECHNICAL FIELD

The present invention relates to a reinforcing bar binder, particularlyrelates to a reinforcing bar binder achieving to increase a bindingstrength and a reinforcing bar binder achieving to improve a finishstate of binding. Further, the invention relates to a binding line feedmechanism of a reinforcing bar binder, particularly relates to a bindingline feed mechanism of a reinforcing bar binder achieving to promotestability in feeding a binding line.

BACKGROUND ART

A reinforcing bar binder is provided with a binding line feed mechanismfor feeding out a binding line of a wire or the like wound around a reelto wind around reinforcing bars, a grasp mechanism for grasping thebinding line wound around the reinforcing bars and a binding line twistmechanism for twisting the binding line by driving to rotate the graspmechanism and carries out winding operation of 1 cycle by successivelyoperating the binding line feed mechanism, the grasp mechanism and thebinding line twist mechanism.

When a nose in a circular arc shape of the reinforcing bar binder ishung around the reinforcing bars and a trigger lever is pulled, thebinding line is fed out along an inner peripheral face of the nose bythe binding line feed mechanism to form a binding line loop at asurrounding of the reinforcing bars, a rear end of the binding line loopis cut by a pivoting type cutter blade provided at a binding line feedpath, a pair of hook type hooks of the binding line grasp mechanism areclosed to grasp the binding line loop and thereafter, the hooks aredriven to rotate by the binding line twist mechanism to twist thebinding line to bind the reinforcing bars.

However, when the hooks of the binding line twist mechanism grasp totwist the binding line which is loosely wound around the reinforcingbars, owing to a structure of rotating the hooks at a constant positionor rotating the hooks while moving forward, there is a case of twistingthe binding line in a state in which tension is not applied thereto andin such a case, there is a case in which the binding line loop afterbinding is not brought into close contact with the reinforcing bars andbinding cannot be carried out solidly. Hence, there poses a technicalproblem to be resolved in order to stabilize the binding strength of thereinforcing bars and it is a first object of the invention to resolvethe above-described problem.

Further, the reinforcing bar binder of the prior art is constituted tocatch a middle portion of the binding line loop remote from a front endthereof and the rear end by the pair of hooks and this is because when aportion of the binding line proximate to the front end or the rear endis caught, in rotating the hooks, the front end or the rear end of thebinding line is drawn out from the hooks to loosen the loop and bindingcannot be carried out. Therefore, lengths of a front end portion and arear end portion of the binding line extended from the portion of thebinding line grasped and twisted by the hooks are prolonged, theportions are projected at the surrounding of the reinforcing bars tobring about a drawback that when concrete is cast, the binding line maybe projected from a surface of the concrete and an amount of consumingthe binding line is large.

Hence, there poses a technical problem to be resolved in order toimprove binding finish by making an extra portion projected from thetwisted portion of the binding line as less as possible and it is asecond object of the invention to resolve the above-described problem.

Further, according to the binding line feed mechanism of the reinforcingbar binding of the prior art, a driven gear with a V-groove is broughtin mesh with a drive gear with a V-groove driven by a feed motor, thedriven gear with the V-groove is attached to one end of a lever and thedriven gear with the V-groove is brought into elastic contact with thedrive gear with the V-groove by a spring interposed at the lever. Whenthe binding line of a wire or the like is passed into the V-grooves ofthe two gears with the V-grooves, the binding line is pinched by thepair of gears with the V-grooves brought in mesh with each other and thebinding line is fed to a nose of the reinforcing bar binder by rotatingthe feed motor.

According to the binding line feed mechanism of the reinforcing barbinder of the prior art in which the driven gear with the V-groove isbrought into elastic contact with a single piece of the drive gear withthe V-groove by the spring, when linearity of the binding line woundaround the binding line reel is poor and a shift in a left and rightdirection is large relative to a moving forward direction, there is acase in which the driven gear with the V-groove is pressed in a lateraldirection by the binding line to disengage from being brought in meshwith the drive gear with the V-groove and a failure in feeding thebinding line is brought about. When a predetermined length of thebinding line is not fed, a failure in binding is brought about in atwisting step, binding operation is obliged to carry out again and alsothe biding line is wasted. Hence, there poses a technical problem to beresolved in order to prevent a failure in feeding from being broughtabout by promoting stability of feeding the binding line and it is athird object of the invention to resolve the above-described problem.

DISCLOSURE OF THE INVENTION

The invention is proposed to achieve the above-described objects, andthere is provided a reinforcing bar binder characterized in an electrictype reinforcing bar binding comprising a binding line feed mechanismfor feeding out a binding line in a loop-like shape to be wound around areinforcing bar, and a binding line twist mechanism for binding thereinforcing bar by twisting the binding line by driving to rotate thegrasping means, wherein a shaft of the grasping means is slidable bymeans of a spline, a serration or the like, further comprising a slidedrive mechanism for elongating and contracting the grasping means andfurther comprising control means for applying a tension to the bindingline wound around the reinforcing bar by controlling the slide drivemechanism in a twisting step.

Further, there is provided the reinforcing bar binder further includingcontrol means for applying the tension to the binding line by movingrearward the grasping means in starting the twisting step by the bindingline twist mechanism and moving forward the grasping means in accordancewith progress of twisting.

Further, there is provided the reinforcing bar binder further comprisingposition detecting means for detecting positions of elongating andcontracting the grasping means and control means for controlling adirection of elongating and contracting the grasping means in accordancewith detected values of the positions wherein the control portioncarries out a control of applying the tension to the binding line bymoving rearward the grasping means to a prescribed position in startingthe twisting step by the binding line twist mechanism and moving forwardthe grasping means in accordance with progress of twisting.

Further, there is provided the reinforcing bar binder further comprisingmeans for slidably driving the grasping means in a front and reardirection by a slide motor and detecting loads for driving the slidemotor and a twist motor for driving to rotate the grasping means, andcontrol means for controlling a direction of rotating the slide motor inaccordance with detected values of the drive loads, wherein the controlportion carries out a control of applying the tension to the bindingline by moving rearward the grasping means in starting the twisting stepby the binding line twist mechanism and moving forward the graspingmeans by reversing the direction of rotating the slide motor when thetwist load or the slide drive load reaches an upper limit value.

Further, in order achieve the above-described objects the inventionprovides a reinforcing bar binder constituted such that in an electrictype reinforcing bar binder comprising a binding line feed mechanism forfeeding out a reinforcing bar binding line of an iron line or the likein a loop-like shape to be wound around the reinforcing bar, a graspmechanism for grasping the binding line wound around the reinforcing barand a binding line twist mechanism for twisting the binding line bydriving to rotate the grasp mechanism, further comprising a slide drivemechanism for moving the binding line grasp mechanism in a front andrear direction and a cutter block provided to a main body of thereinforcing bar binder, wherein the binding line grasped by the bindingline grasp mechanism is sheared between the binding line grasp mechanismand the cutter block by sliding the binding line grasp mechanismrelative to the cutter block.

Further, there is provided the reinforcing bar binder further comprisinga slide guide block opposed to the cutter block by interposing thebinding line grasp mechanism therebetween, wherein the bind line graspmechanism is guided by pinching the binding line grasp mechanism by thecutter block and the slide guide block.

Further, in order to achieve the above-described object, the inventionprovides a binding line feed mechanism of a reinforcing bar bindercharacterized in a binding line feed mechanism of a reinforcing barbinding for bringing a drive gear with a V-groove and a driven gear witha V-groove formed with the V-grooves in peripheral directions at outerperipheral faces thereof, which is the binding line feed mechanism ofthe reinforcing bar binder for bringing the driven gear with theV-groove into elastic contact with the drive gear with the V-groove by aspring and pinching a binding line between the V-grooves of the drivegear with the V-groove and the driven gear with the V-groove, wherein aplurality of the drive gears with the V-grooves are arranged along apath of the binding line and the driven gears with the V-grooves arebrought into elastic contact with respectives of the plurality of drivegears with the V-grooves by the spring.

Further, there is provided the binding line feed mechanism of areinforcing bar binder characterized in arranging the plurality of drivegears with the V-grooves along the path of the binding line, attachingthe plurality of driven gears with the V-grooves to one gear holder,attaching the gear holder pivotably and slidably in a direction of thedrive gears with the V-grooves and urging the gear holder in thedirection of the drive gears with the V-grooves by a spring to bring theplurality of driven gears with the V-grooves respectively into elasticcontact with the drive gears with the V-grooves opposed thereto.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side sectional view showing a mechanism portion of areinforcing bar binder according to the invention.

FIG. 2 is a plane sectional view showing the mechanism portion of thereinforcing bar binder according to the invention.

FIG. 3 is a front view showing the mechanism portion of the reinforcingbar binder according to the invention.

FIG. 4( a) and FIG. 4( b) show a binding line feed mechanism of thereinforcing bar binder, FIG. 4( a) is a front view and FIG. 4( b) is aside sectional view.

FIGS. 5( a) through 5(c) show a step of forming a path of a binding lineof the reinforcing bar binder, FIG. 5( a) is a plane sectional view,FIG. 5( b) is a front view and FIG. 5( c) is a side sectional view.

FIGS. 6( a) through 6(c) show a step of feeding the binding line, FIG.6( a) is a plane sectional view, FIG. 6( b) is a front view and FIG. 6(c) is a side sectional view.

FIGS. 7( a) through 7(c) show a step of grasping the binding line, FIG.7( a) is a plane sectional view, FIG. 7( b) is a front view and FIG. 7(c) is a side sectional view.

FIGS. 8( a) through 8(c) show a step of pulling back the binding line ofa binding line twist mechanism, FIG. 8( a) is a plane sectional view,FIG. 8( b) is a front view and FIG. 8( c) is a side sectional view.

FIGS. 9( a) through 9(c) show a step of refeeding the binding line, FIG.9( a) is a plane sectional view, FIG. 9( b) is a front view and FIG. 9(c) is a side sectional view.

FIGS. 10( a) through 10(c) show a step of grasping the binding line,FIG. 10( a) is a plane sectional view, FIG. 10( b) is a front view andFIG. 10( c) is a side sectional view.

FIGS. 11( a) through 11(c) show a step of cutting the binding line, FIG.11( a) is a plane sectional view, FIG. 11( b) is a front view and FIG.11( c) is a side sectional view.

FIGS. 12( a) through 12(c) show a step of tightening the binding line,FIG. 12( a) is a plane sectional view, FIG. 12( b) is a front view andFIG. 12( c) is a side sectional view.

FIG. 13( a) and FIG. 13( b) show a twisting step, FIG. 13( a) is a frontview and FIG. 13( b) is a side sectional view.

FIGS. 14( a) through 14(c) show a state of finishing to twist, FIG. 14(a) is a plane sectional view, FIG. 14( b) is a front view and FIG. 14(c) is a side sectional view.

FIGS. 15( a) through 15(c) show a step of releasing the binding line,FIG. 15( a) is a plane sectional view, FIG. 15( b) is a front view andFIG. 15( c) is a side sectional view.

FIG. 16 is a side sectional view showing a second embodiment and showingan initial state of a mechanism portion of a reinforcing bar binder.

FIG. 17 is a side sectional view showing a step of tightening a bindingline of the reinforcing bar binder of FIG. 16.

FIG. 18 is a side sectional view showing a mechanism portion of areinforcing bar binder according to the invention.

FIG. 19 is a plane sectional view showing the mechanism portion of thereinforcing bar binder according to the invention.

FIG. 20 is a front view showing the mechanism portion of the reinforcingbar according to the invention.

In FIGS. 21( a) through 21(f), FIG. 21( a) is a front view a right clampplate, FIG. 21( b) is a side view of the right clamp plate, FIG. 21( c)is a front view of a center clamp plate, FIG. 21( d) is a side view ofthe center clamp plate, FIG. 21( e) is a front view of a left clampplate and FIG. 21( f) is a side view of the left clamp plate.

FIGS. 22( a) through 22(c) show an initial state of a twist mechanismportion, FIG. 22( a) is a plane view, FIG. 22( b) is a front view andFIG. 22( c) is a side sectional view.

FIGS. 23( a) through 23(c) show a step of feeding a binding line, FIG.23( a) is a plane view, FIG. 23( b) is a front view and FIG. 23( c) is aside sectional view.

FIGS. 24( a) through 24(c) show a step of pulling back the binding line,FIG. 24( a) is a plane view, FIG. 24( b) is a front view and FIG. 24( c)is a side sectional view.

FIGS. 25( a) through 25(c) show a step of grasping the binding line,FIG. 25( a) is a plane view, FIG. 25( b) is a front view and FIG. 25( c)is a side sectional view.

FIGS. 26( a) through 26(c) show a step of cutting the binding line, FIG.26( a) is a plane view, FIG. 26( b) is a front view and FIG. 26( c) is aside sectional view.

FIG. 27( a) and FIG. 27( b) show a step of twisting the binding line,FIG. 27( a) is a front view and FIG. 27( b) is a side sectional view.

FIG. 28( a) and FIG. 28( b) show a state of finishing to twist thebinding line, FIG. 28( a) is a front view and FIG. 28( b) is a sidesectional view.

FIGS. 29( a) through FIG. 29( c) show a step of releasing a clamp plate,FIG. 29( a) is a plane view, FIG. 29( b) is a front view and FIG. 29( c)is a side sectional view.

Note that in the drawings, numeral 1 designates a binding line feedmechanism, numeral 2 designates a binding line twist mechanism, numeral6 designates a circular arc shape nose, numeral 7 designates a baseplate, numerals 8, 9 designates drive gears with V-grooves, numerals 10,11 designates driven gears with V-grooves, numeral 12 designates amiddle gear, numeral 13 designates a feed motor, numeral 14 designates areduction gear, numeral 15 designates a gear holder, numeral 16designates a long hole, numeral 17 designates a pin, numeral 18designates a lever, numeral 19 designates a spring receive seat, numeral20 designates a compression coil spring, numeral 21 designates a twistmotor, numeral 22 designates a slide motor, numeral 23 designates afinal gear, numeral 24 designates a ball screw shaft, numeral 25designates a binding line clamp apparatus, numeral 26 designates acenter clamp plate, numeral 27 designates a right clamp plate, numeral28 designates a left clamp plate, numeral 29 designates a sleep, numeral30 designates a ball holding ring, numeral 31 designates a rotationstopping fin, numeral 32 designates a shifter disk, numeral 33designates a ball screw shaft, numeral 34 designates a ball holdingring, numeral 35 designates a guide pin (center clamp plate), numeral 36designates a guide pin (sleeve), numeral 37 designates a guide pin(sleeve), numeral 38 designates a groove cam (left and right clampplates), numeral 39 designates a guide groove (right clamp plate),numeral 40 designates a recess (left clamp plate), numeral 301designates a binding line twist mechanism, numeral 302 designates abinding line feed mechanism, numeral 304 designates a cutter block,numeral 305 designates a binding line guide hole, numeral 306 designatesa circular arc shape nose, numeral 307 designates a twist motor, numeral308 designates a slide motor, numeral 311 designates a ball screw shaft,numeral 312 designates a binding line clamp apparatus, numeral 313designates a right clamp plate, numeral 314 designates a center clampplate, numeral 315 designates a left clamp plate, numeral 316 designatesa sleeve, numeral 317 designates a binding line guide groove, numeral318 designates a recess, numerals 319, 320 designate guide pins,numerals 321, 322 designate groove cams, numeral 323 designates a guidepin, numeral 324 designates a pin hole, numeral 326 designates shifterdisk, numeral 333 designates a feed motor and numeral 335 designates aslide guide block.

MODE FOR CARRYING OUT THE INVENTION

A detailed description will be given of a first embodiment of theinvention in reference to the drawings as follows. FIG. 1 through FIG. 3show the binding line feed mechanism 1 and the binding line twistmechanism 2 of a reinforcing bar binder which are included in a casing(not illustrated) having a grip similar to a hand-held tool of a nailingmachine or the like. A wire wound around a wire reel (not illustrated)is supplied to the circular arc shape nose 6 through a binding lineguide hole 5 of a cutter block 4 provided at a nose portion 3 by thebinding line feed mechanism 1.

FIG. 4 shows the binding line feed mechanism 1, the drive gears withV-grooves 8, 9 are arranged above the base plate 7 in a front and reardirection along a moving forward direction of a wire W and driven gearswith V-grooves 10, 11 are respectively brought in mesh with two frontand rear pieces of the drive gears with V-grooves 8, 9. Two pieces ofthe drive gears with V-grooves 8, 9 are brought in mesh with the middlegear 12, power is transmitted from the feed motor 13 via the reductiongear 14 and the middle gear 12 and two pieces of the drive gears withV-grooves 8, 9 are rotated in synchronism with each other.

Two front and rear pieces of the driven gears with V-grooves 10, 11 areattached to the gear holder 15 in a bell crank shape. A middle portionof the gear holder 15 is formed with the long hole 16 in a directionorthogonal to a direction of feeding the wire and the pin 17 provided atthe base plate 7 is engaged with the long hole 16 to hold the gearholder 15 pivotably in a front and rear direction and in a left andright direction. The base plate 7 is attached with the lever 18 forcoupling a front end portion of the lever 18 and a rear end portion(right end portion in the drawing) of the rear holder 15 by a pin. Thecompression coil spring 20 is interposed between a rear end portion ofthe lever 18 and the spring receive seat 19 provided above the baseplate 7, the front end portion of the lever 18 and the gear holder 15are urged in a direction of the drive gears with V-grooves 8, 9 opposedthereto and two pieces of the driven gears with V-grooves 10, 11 arerespectively brought into elastic contact with the drive gears withV-grooves 8, 9.

In using the reinforcing bar binder, when the rear end portion of thelever 18 is pressed by the finger to pivot the lever 18, the gear holder15 is moved rearward and two pieces of the driven gears with V-grooves10, 11 are separated from the drive gears with V-grooves 8, 9 and whenthe front end portion of the wire W drawn out from the wire reel ispassed between the drive gears with V-grooves 8, 9 and the driven gearswith V-grooves 10, 11 and pressing by the lever 18 is released, the wireW is pinched between the V-grooves of the drive gears with V-grooves 8,9 and the driven gears with V-grooves 10, 11 and the drive gears withV-grooves 8, 9 and the driven gears with V-grooves 10, 11 are brought inmesh with each other to prepare for use.

When linearity of the wire is poor, in drawing in the wire by the drivegear with the V-groove 8 and the driven gear with the V-groove 10 on theupstream side (lower side in the drawing), the driven gear with theV-groove 10 may be pressed in a lateral direction to separate from thedrive gear with the V-groove 8, at this occasion, the gear holder 15 ispivoted by constituting a fulcrum by the pin 17 and the driven gear withthe V-groove 1 on the downstream side stays to be brought in mesh withthe drive gear with the V-groove 9 and the wire W is continued to feed.Further, even when the drive gear with the V-groove 9 and the drivengear with the V-groove 11 on the downstream side are disengaged frombeing brought in mesh with each other by local irregularities of thewire passing the drive gear with the V-groove 8 and the driven gear withthe V-groove 10 on the upstream side, the driven gear with the V-groove8 and the drive gear with the V-groove 10 on the upstream side stay tobe brought in mesh with each other and the wire is not stopped to feed.

Next, an explanation will be given of the binding line twist mechanism2. As shown by FIG. 1 and FIG. 2, the binding line twist mechanism 2includes two motors of the twist motor 21 and the slide motor 22 and thetwist motor 21 drives the final gear 23 via a reduction gear train. Theball screw shaft 24 is fitted to a center hole of the final gear 23 by aspline. A male screw is formed at a front end portion of the ball screwshaft 24 and a front end thereof is rotatably coupled with a shaftportion of the center clamp plate 26 constituting a portion of thebinding line clamp apparatus 25. The binding line clamp apparatus 25comprises the center clamp plate 26, the clamp plates 27, 28 arranged onthe left and on the right of the center clamp plate 26, the sleeve 29covering three sheets of the clamp plates 26, 27, 28 and the ballholding ring 30 fitted to a rear end of the sleeve 29, and a ball (notillustrated) fitted to a hole of the sleeve 29 is brought in mesh withthe male screw of the ball screw shaft 24.

When the twist motor 21 is rotated in a regular direction, the sleeve 29is moved rearward by rotating the ball screw shaft 24. An outerperiphery of the ball holding ring 30 is radially aligned with therotation stopping fins 31, and at a frontmost position which is aninitial position, the rotation stopping fins 31 of the ball holding ring30 are engaged with rotation stopping claws (not illustrated) providedat the casing and the binding line clamp apparatus 25 is brought into anunrotatable state.

A middle portion of the ball screw shaft 24 is attached with the shifterdisk 32 rotatable relative to the ball screw shaft 24. The shifter disk32 is connected to the ball holding ring 34 screwed to the ball screwshaft 33 of the slide motor 22, and the ball screw shaft 24 and thebinding line clamp apparatus 25 of the binding line twist mechanism aremoved in the front and rear direction in accordance with a direction ofrotating the slide motor 22.

The left and right clamp plates 27, 28 can be slid in parallel with eachother to the left and to the right along the guide pin 35 provided atthe center clamp late 26, and the guide pins 36, 37 provided at theclamp plates 27, 28 are engaged with the groove cams 38 formed at innerperipheral faces of the sleeve 29. The groove cams 38 are constituted bya cam shape by which when the sleeve 29 is moved rearward, the left andright lamp plates 27, 28 are made to be proximate to each other andfinally, the left and right clamp plates 27, 28 pinch the center lampplate 26.

Next, an explanation will be given of operation of the reinforcing barbinder. FIG. 1 through FIG. 3 show an initial state and when a triggeris pulled from the state, the twist motor 21 is rotated in the regulardirection by a predetermined rotational number and as shown by FIG. 5,the sleeve 29 is moved rearward and the left and right clamp plates 27,28 are lightly closed. The clamp plate 27 on the right side in view froman operator (upper side in FIG. 5( a)) is formed with a binding lineguide groove 39 constituting a path of feeding out the wire. The clampplate 28 on the left side is formed with the recess 40 in a channel-likeshape reaching a lower end of the inner side face from an upper portionthereof and in a successive step of feeding the wire, the wire isintroduced from the lower side to the recess 40 of the clamp plate 28.

Successively, as shown by FIG. 6, the feed motor 13 is started and thewire W reeled out to the circular arc shape nose 6 through the guidegroove 39 of the clamp plate 27 on the right side by rotating two frontand rear pairs of the drive gears with V-grooves 8, 9 and the drivengears with V-grooves 10, 11 is bent in a loop shape along a shape of aguide groove at an inner periphery of the circular arc shape nose 6 andthe front end moves forward from an opening of a lower face of the clampplate 28 on the left side into the recess 40 and impinges on a ceilingportion of the recess portion 40 to stop. An amount of feeding the wireW is controlled by a control apparatus (not illustrated). Further,notation S designates a reinforcing bar.

After stopping the feed motor 13, the twist motor 21 is started and asshown by FIG. 7, the sleeve 29 is further moved rearward and the clampplate 28 on the left side is brought into press contact with the centerclamp plate 26 to pinch the front end portion of the wire W.Successively, as shown by FIG. 8, the wire W is pulled back by reverselydriving the feed motor 13, the wire W is wound around the reinforcingbar S and thereafter, as shown by FIG. 9, the feed motor is regularlydriven to rotate to feed out the wire W by a prescribed length. This isfor making an amount of projecting a knot portion uniform by making atwist margin of the wire W constant length regardless of a boldness of abundle of the reinforcing bar to be wound.

Further, as shown by FIG. 10, the sleeve 29 is further moved rearward,the wire W is solidly pinched by the left and right clamp plates 27, 28and the center clamp plate 26 and as shown by FIG. 11, the slide motor22 is regularly driven to rotate to move rearward the ball screw shaft24 and the binding line clamp apparatus 25. By moving the binding lineclamp apparatus 25 in parallel relative to the binding line guide hole 5of the cutter block 4, the wire W is sheared at a position of slidingfaces of the guide groove 39 of the left clamp plate 27 and the bindingline guide hole 5.

Further, as shown by FIG. 12, the binding line clamp apparatus 25 isfurther moved rearward to apply tension to the wire W and when drivecurrent reaches a prescribed upper limit value by increasing drive loadof the slide motor 22, the slide motor 22 is stopped. Further, in thetightening step, after previously intersecting the grasped wire W byrotating the binding line clamp apparatus 25 by half rotation, thebinding line clamp apparatus 25 may be moved rearward.

Next, the twist motor 21 is regularly driven to rotate and the bindingline clamp apparatus 25 is rotated as shown by FIG. 13, since therotation stopping fins 31 of the ball holding ring 30 moved rearwardfrom the initial position are detached from the rotation stopping clawsof the casing and the bold screw 24 and the binding line clamp apparatus25 is moved forward by reversely driving to rotate the slide motor 22and the biding line clamp apparatus 25 to twist the wire W whileapproaching the reinforcing bar S.

Further, when the binding line clamp apparatus 25 is moved forward by aprescribed distance as shown by FIG. 14, or when the drive currentreaches the prescribed upper limit value by increasing the drive load ofthe twist motor 21 in finishing to twist, the twist motor 21 and theslide motor 22 are stopped to drive. Successively, as shown by FIG. 15,the twist motor 21 is reversely rotated and the sleeve 29 is movedforward to thereby open the left and right clamp plates 27, 28 andrelease the wound wire W and thereafter, the binding line clampapparatus 25 is returned to the initial position by controlling thetwist motor 21 and the slide motor 22 to thereby finish the bindingoperation of 1 cycle.

Further, an amount of moving the binding line clamp apparatus 25 in thefront and rear direction is detected by a rotational number of the slidemotor 22 and when the binding line clamp apparatus 25 reaches the frontinitial position, the slide motor 22 is stopped. Further, drive currentsof the slide motor 22 and the twist motor 21 are detected and when thedrive currents reaches the upper limit value before the amount of movingthe binding line clamp apparatus 25 reaches a set value, the wire isprevented from being broken by being applied with excessive tension bycontrolling to enter a successive step.

Further, the drive currents of the twist motor 21 and the slide motor 22and the rotational direction of the slide motor 22 may be control by afeedback control such that constant tension is applied on the wire Wbased on the detected value of the drive currents and in this case,simultaneously with starting the tightening step in FIG. 9, at aninitial stage of twisting, the binding line clam apparatus 25 can becontrolled to move rearward by starting to rotate the binding clampapparatus 25 and thereafter, the binding line clamp apparatus 25 can becontrolled to return to the twist finish position by moving forward thebinding line clamp apparatus 25 in accordance with tension thereafterand operational speed of 1 cycle can be accelerated.

FIG. 16 shows a second embodiment in which a slit plate 41 is attachedto the ball holding ring 34 connected to the shifter disk 32, an opticalposition sensor is constituted by the slit plate 41 and aphotointerrupter 42 arranged at a frame (not illustrated) and the slidemotor 22 is controlled to drive by detecting a position of the bindingline clamp apparatus 25 in the front and rear direction by way of theslit plate 41. FIG. 16 shows an initial state, the slide motor 22 isdriven to rotate regularly after grasping the wire similar to theabove-described embodiment, the ball screw shaft 24 and the binding lineclamp apparatus 25 are moved rearward to the prescribed position asshown by FIG. 17, tension is applied thereto and the wire is cut. In thetwisting step, the slide motor 22 is driven to rotate reversely tothereby move forward the binding line clamp apparatus 25 and when thebinding line clamp apparatus 25 returns to the initial position, theslide motor 22 is stopped.

Further, in the clamping step of FIG. 7, the left and right clamp plates27, 28 may be constituted to simultaneously clamp the wire W by changingthe shapes of the groove cams 38 of the sleeve 29 to thereby omit thestep of clamping the rear end portion of the wire shown in FIG. 10.Further, although according to the above-described embodiment, thegroove cams 38 are formed at the left and right clamp plates 27 and 28,the guide pins 36, 37 are provided at the sleeve 29, contrary thereto,there may be constructed a constitution of forming the groove cams atthe sleeve 29 and providing the guide pins at the left and right clampplates 27, 28.

Further, when it is not necessary to uniformly control a projectedamount of the twisted portion by constituting the twist margin of thewire W by a constant length, the operational speed of 1 cycle can beaccelerated by omitting the step of pulling back the wire of FIG. 8, thestep of refeeding the wire of FIG. 9 and the tightening step of FIG. 12and a normal operation mode and the above-described high speed operationmode may be switched as necessary.

Further, the invention is not limited to the above-described embodimentsand although an explanation has been given by taking an example of thewire as the binding line, a wire other than the metal wire may be used.Further, the invention can be modified variously within the technicalrange and the invention naturally covers modified embodiments thereof.

A detailed description will be given of a third embodiment of theinvention in reference to the drawings as follows. FIG. 18 through FIG.20 show the binding line twist mechanism 301 and the binding line feedmechanism 302 which are included in a casing (not illustrated) having agrip similar to a hand-held tool of a nailing machine or the like. Thewire wound around a wire reel (not illustrated) is supplied from thebinding line feed mechanism 302 to the circular arc shape nose 306 bypassing the binding line guide hole 305 of the cutter block 304 providedat a nose portion 303.

The binding line twist mechanism 301 includes two motors of the twistmotor 307 and the slide motor 308 and the twist motor 307 drives a finalgear 310 via a reduction gear 309. The ball screw shaft 311 is fitted toa center hole of the final gear 310 by a spline and the binding lineclamp apparatus 312 is rotatably fitted to a front end of the ball screwshaft 311.

FIGS. 21( a) through 21(f) show three sheets of the clamp plates, 313,314, 315 of the binding line clamp apparatus 312 constituting a bindingline grasp mechanism, and the center clamp plate 314 connected to thefront end of the clamp shaft 312 is integrated with the right clampplate 313 and the left clamp plate 315 and integrated to inside of thesleeve 316 as shown by FIG. 19. As shown by FIGS. 21( a) and 21(b), aninner side face of the right clamp plate 313 is formed with the bindingline guide groove 317 constituting a path of feeding out the bindingline, a width of a lower end portion of the binding line guide groove317 is substantially equal to the diameter of the binding line and anupper portion thereof is constituted by a shape of enlarging the widthand opening a front face thereof. As shown by FIGS. 21( e) and 21(f), aninner side face of the left clamp plate 315 is formed with the recess318 in a channel-like shape reaching a vicinity of an upper end thereoffrom a lower end thereof and a front face of the recess 318 is openedsimilar to the binding line guide groove 317 of the right clamp plate313.

The guide pins 319, 320 are respectively formed at an upper face of arear portion of the right clamp plate 313 and a lower face of a rearportion of the left clamp plate 315. As shown by FIG. 19, the sleeve 316holding three sheets of the clamp plates 313, 314, 315 is formed withthe groove cams 321, 322 in correspondence with the guide pins 319, 320of the left and right clamp plates 313, 315 and when the sleeve 316 ismoved rearward from a front initial position, the left and right clampplates 313, 315 become proximate to each other to pinch the center clampplate 314. Further, the inner side face of the right clamp plate 313 isprovided with the guide pin 323 and by engaging the guide pin 323 to thepin hole 324 provided at the center clamp plate 314, rattling of theright clamp plate 313 when the binding line clamp apparatus 312 moves inthe front and rear direction is prevented to thereby prevent adeterioration of a cutting function in a step of cutting the bindingline, mentioned later.

As shown by FIG. 18, the sleeve 316 is fitted to the ball screw shaft313 and the ball holding ring 325 having rotation stopping pins 325 a isfitted to a rear end portion of the sleeve 316. When the twist motor 307is rotated in the regular direction, the sleeve 316 is moved rearward byrotating the ball screw shaft 311. At a frontmost position constitutingan initial position, the rotation stopping pins 325 a of the ballholding ring 325 are engaged with rotation stopping claws (notillustrated) provided at the casing and the binding line clamp apparatus312 is brought into an unrotatable state.

A middle portion of the ball screw shaft 311 is attached with theshifter disk 326 rotatable relative to the ball screw shaft 311. Theshifter disk 326 is connected to a ball holding ring 328 fitted to aball screw shaft 327 of the slide motor 308 and the ball screw shaft 311and the binding line clamp apparatus 312 of the binding line twistmechanism 301 are moved in the front and rear direction in accordancewith a direction of rotating the slide motor 308.

As shown by FIG. 20, the binding line feed mechanism 302 is constitutedby two pieces of drive gears with V-grooves 329, 330 and two pieces ofdriven gears with V-grooves 331, 332 brought in mesh with the drivegears with V-grooves 329, 330 arranged in a front and rear directionalong a direction of moving forward the wire, two pieces of the drivegears with V-grooves 329, 330 are transmitted with power from the feedmotor 333 shown in FIG. 18 via a reduction gear train 334 and the wireis pinched to feed out by the drive gears with V-grooves 329, 330 andthe driven gears with V-grooves 331, 332.

FIGS. 22( a) through 22(c) show an initial state of the reinforcing barbinder, the binding line clamp apparatus 312 and the sleeve 316 aredisposed at front initial positions and the left and right clamp plates313 and 315 are opened and the binding line guide groove 317 of theright clamp plate 313 coincides with the binding line guide hole 305 ofthe cutter block 304. The slide guide block 335 is provided on the upperside of the cutter block 304, two upper and lower faces of the bindingline clamp apparatus 312 are pinched by the cutter block 304 and theslide guide block 335 and the function of cutting the binding line isstabilized such that a clearance is not produced between the bindingline clamp apparatus 312 and the cutter block 304.

Next, operation of the reinforcing bar binder will be explained. When atrigger is pulled in the initial state shown by FIGS. 22( a) through22(c), the twist motor 307 is rotated in the regular direction by apredetermined rotational number and as shown by FIG. 23( a) through FIG.23( c) the sleeve 316 is moved rearward and the left and right clampplates 313, 315 are lightly closed, however, the left and right clampplates 313, 315 are not brought into close contact with the center clampplates 314 yet. Successively, the feed motor 333 of the binding linefeed mechanism 2 is started and the wire W reeled out to the circulararc shape nose 306 via the binding line guide hole 305 of the cutterblock 304 and the guide groove 317 of the light clamp plate 313 byrotating two front and rear pairs of the drive gears with V-grooves 329,330 and the driven gears with V-grooves 331, 332 is bent in a loop shapealong a shape of a guide groove at an inner periphery of the circulararc shape nose 306 and a front end thereof moves forward from theopening of the lower face of the left cam plate 315 into the recess 318and impinges on a ceiling portion of the recess 318 to stop. An amountof feeding the wire W is controlled by a control apparatus (notillustrated). Further, notation S designates a reinforcing bar.

After stopping the feed motor 333, the twist motor 307 of the bindingline twist mechanism 301 is started, as shown by FIGS. 24 a through 24c, the sleeve 316 is further moved rearward, the left clamp plate 315 isbrought into contact with the center clamp plate 314 to pinch the frontend of the wire W and the wire W is pulled back by reversely driving torotate the feed motor 333 to wind the wire W around the reinforcing barS.

Successively, as shown by FIGS. 25( a) through 25(c), the sleeve 316 isfurther moved rearward, also the right clamp plate 313 is closed tosolidly pinch the wire W and the slide motor 308 is driven to rotateregularly to move rearward the binding line clamp apparatus 312 as shownby FIGS. 26( a) through 26(c). The rear end portion of the wire W woundaround the reinforcing bar S is sheared by moving the wire W grasped bythe binding line clamp apparatus 312 relative to the binding line guidehole 305 of the cutter block 304 in parallel therewith.

Further, as shown by FIGS. 27( a) and 27(b), the wire W is twisted byrotating the binding line clamp apparatus 312 by driving to rotate thetwist motor 307 regularly and detaching the rotation stopping is pins325 a of the ball holding ring 325 moved rearward from the initialposition from the rotation stopping claws of the casing. FIG. 28( a) andFIG. 28( b) show a state of finishing to twist, the front end and therear end of the wire loop are clamped to twist and therefore, a lengthof an extra portion extended from the knot portion of the wire is shortand finish is beautiful.

Successively, by moving forward the sleeve 316 by reversely rotating thetwist motor 307, as shown by FIGS. 29( a) through 29(c), the left andright clamp plates 313, 315 are opened, the grasped wire W is releasedand thereafter, the binding line clamp apparatus 312 is returned to theinitial position shown by FIGS. 22( a) through 22(c) by controlling thetwist motor 307 and the slide motor 308 to thereby finish bindingoperation of 1 cycle.

Although the above-described embodiment is constituted by a structure ofsliding the binding line clamp apparatus 312 in the front and reardirection by the slide motor 308, there can also be constructed aconstitution of one motor for shearing the binding line by sliding thebinding line clamp apparatus 312 by rotating the twist motor 307 and theball screw shaft 311 without using the slide motor 308. Further,although the binding line clamp apparatus 312 is formed with the groovecams 321, 322 at the sleeve 316 and the guide pins 319, 320 of the leftand right clamp plates 313, 315 are engaged with the groove cams 321,322, contrary thereto, there may be constructed a constitution in whichthe groove cams are formed at the clamp plates 313, 315 and the guidepins are provided at the sleeve 316. Further, although an explanationhas been given of an example of the wire as the binding line, a wireother than the metal wire may be used.

Further, the invention is not limited to the above-described embodimentsbut can variously be modified within the technical range of theinvention and the invention naturally covers modified embodimentsthereof.

The present application is based on Japanese Patent Application(Japanese Patent Application No. 2001-220598) filed on Jul. 19, 2001,Japanese Patent Application (Japanese Patent Application No.2001-225201) filed on Jul. 25, 2001 and Japanese Patent Application(Japanese Patent Application No. 2001-241342) filed on Aug. 8, 2001 andcontents thereof are incorporated here by reference.

INDUSTRIAL APPLICABILITY

As has been explained above, according to the reinforcing bar binder ofthe invention, after grasping the binding line wound around thereinforcing bar by the binding line feed mechanism by the grasping meansof the binding line twist mechanism, the twisting shaft attached withthe grasping means is contracted, and the binding line is twisted in astate of applying tension thereto, and therefore, reinforcing barbinding strength of the binding line loop is stabilized and a failure inbinding can be prevented from being brought about.

Further, stable binding can be carried out without breaking the bindingline by applying tension to the binding line by contracting the twistingshaft in starting the twisting step and elongating the twisting shaft inaccordance with progress of twisting.

Further, the reinforcing bar binder of the invention is constituted suchthat the binding line grasp mechanism is constituted by the opening andclosing type clamp plates and shearing the binding line by an end faceof the clamp plates by sliding the binding line grasp mechanism andtherefore, the binding line can be twisted up to vicinities of both endsthereof in the twisting step for rotating the binding line graspmechanism and different from the reinforcing bar binder of the priorart, the both ends of the binding line are not projected at thesurrounding of the reinforcing bar and excellent finish can be achieved.

Further, a clearance is not produced between the clamp plate and thecutter block by sliding the clamp plate along the cutter block bypinching the two upper and lower faces of the clamp plates of thebinding line grasp mechanism by the cutter block and the slide guideblock and the function of cutting the binding line is stabilized.

Further, the binding line feed mechanism of the reinforcing bar binderof the invention is arranged with two sets of the feed mechanisms by thegears with V-grooves in the front and rear direction at the path offeeding the binding line and therefore, even when the gears withV-grooves on the upstream side are disengaged from being brought in meshwith each other by bending the binding line, the gears with V-grooves onthe downstream side are brought in mesh with each other and therefore,feeding is not stopped or becomes unstable, the amount of feeding thebinding line can be controlled constant and the binding function of thereinforcing bar binder is promoted.

1. A reinforcing bar binder comprising: a binding line feed mechanismthat feeds out a binding line in a loop-like shape to be wound around areinforcing bar; a grasp mechanism having a slidable shaft, the graspmechanism including a plurality of clamp plates that open and close ontothe binding line wound around the reinforcing bar; a binding line twistmechanism that binds the reinforcing bar by twisting the binding line bydriving to rotate the grasp mechanism; a slide drive mechanism forelongating and contracting the grasp mechanism; a control portion thatapplies a tension to the binding line wound around the reinforcing barby controlling the slide drive mechanism in a twisting step; a feedmotor that drives the binding line feed mechanism; a slide motor thatdrives the slide drive mechanism; a twist motor that drives the graspmechanism and the binding line twist mechanism; and a rotation stoppingfin that is slidable between a first position and a second position,wherein the grasp mechanism is unrotatable when the rotation stoppingfin is in the first position and the grasp mechanism is rotatable whenthe rotation stopping fin is in the second position.
 2. The reinforcingbar binder according to claim 1, wherein the control portion applies thetension to the binding line by moving rearward the grasp mechanism instarting the twisting step, and moves forward the grasp mechanism inaccordance with progress of twisting.
 3. The reinforcing bar binderaccording to claim 1, further comprising: a position detecting meansthat detects positions of elongating and contracting the graspmechanism; and wherein, in accordance with detected values detected bythe position detecting means, the control portion controls elongating orcontracting motion of the grasp mechanism; and wherein the controlportion applies the tension to the binding line by moving rearward thegrasp mechanism to a prescribed position in starting the twisting step,and moves forward the grasp mechanism in accordance with progress oftwisting.
 4. The reinforcing bar binding according to claim 1, furthercomprising: a slide motor; a twist motor; and a detecting portion thatdetects driving loads of the slide motor and the twist motor, the slidemotor drives to slide the grasp mechanism in a front and rear direction,and the twist motor drives to rotate the grasp mechanism; wherein thecontrol portion controls a rotating direction of the slide motor inaccordance with detected values of the drive loads; and wherein thecontrol portion applies the tension to the binding line by movingrearward the grasp mechanism in starting the twisting step, and movesforward the grasp mechanism by reversing the rotating direction of theslide motor when the twist load or the slide drive load reaches an upperlimit value.
 5. A reinforcing bar binder comprising: a binding line feedmechanism that feeds out a binding line in a loop-like shape to be woundaround a reinforcing bar; a grasp mechanism including an opening andclosing type clamp plate that grasps the binding line wound around thereinforcing bar; a binding line twist mechanism that twists the bindingline by driving to rotate the grasp mechanism; a slide drive mechanismthat moves the grasp mechanism in a front and rear direction; and acutter block, a binding line guide hole provided on the cutter block;and a guide groove provided on the grasp mechanism, wherein the bindingline feed mechanism feeds out the binding line through the binding lineguide hole and the guide groove, the binding line grasped by the graspmechanism is sheared between the grasp mechanism and the cutter block bysliding the grasp mechanism relative to the cutter block, and thebinding line guide hole guides the binding line in a directiontransverse to a direction that the grasp mechanism slides relative tothe cutter block.
 6. The reinforcing bar binder according to claim 5,further comprising: a slide guide block opposed to the cutter block byinterposing the grasp mechanism, wherein the grasp mechanism is guidedby pinching the grasp mechanism by the cutter block and the slide guideblock.
 7. The reinforcing bar binder according to claim 1, when therotation stopping fin is in the second position, the grasp mechanism isdriven to grasp the binding line by the twist motor, when the rotationstopping fin is in the first position, the binding line twist mechanismis driven to twist the binding line by the twist motor.